Symptoms:

Adults and the nymps suck leaf sap from the under surface of the lower leaves.

When the infestation is heavy, leaves turn yellowish white and wither away.

Due to continuous desapping by large number of hoppers top leaves in the affected canes dry up and lateral buds germinate. The hoppers exude a sweet sticky fluid known as honeydew, which promotes quick and luxuriant growth of the fungus, capanodium species and as a result the leaves are completely covered by the sooty mould.